Air conditioner

ABSTRACT

An air conditioner performs heating operation by driving a compressor ( 21 ), the heating operation being performed while an indoor heat exchanger ( 13 ) serves as the high-temperature portion of refrigeration cycle and an outdoor heat exchanger ( 23 ) serves as the low-temperature portion of the refrigeration cycle. The air conditioner also performs defrosting operation for defrosting the outdoor heat exchanger ( 23 ) by flowing refrigerant in opposite direction of flow of the refrigerant in the heating operation. In the outdoor heat exchanger ( 23 ), a large number of fins ( 30 ) are affixed to refrigerant pipes ( 2 ) so as to close to each other. Air flow passes through between the fins ( 30 ) to perform heat exchange. A water introduction section ( 31, 32 ) for closing each of the gaps between the fins ( 30 ) at one end thereof in the air flow passage direction is provided at the lower end of the outdoor heat exchanger ( 23 ).

TECHNICAL FIELD

The present invention relates to an air conditioner that performs awarming operation and a defrosting operation.

BACKGROUND ART

A conventional air conditioner is disclosed in a patent document 1. Thisair conditioner includes an indoor apparatus disposed indoors and anoutdoor apparatus disposed outdoors. The outdoor apparatus is providedwith a compressor, an outdoor heat exchanger, and an outdoor fan, whilethe indoor apparatus is provided with an indoor heat exchanger and anindoor fan. The compressor flows a refrigerant to operate arefrigeration cycle. In the indoor heat exchanger and outdoor heatexchanger, a refrigerant pipe is mounted with many fins close to oneanother and performs heat exchange with air passing through between thefins.

A refrigerant outlet portion of the compressor is connected to one endof the indoor heat exchanger and one end of the outdoor heat exchangerrespectively via a four-way valve by means of the refrigerant pipe. Theother ends of the indoor heat exchanger and the outdoor heat exchangerare connected via an expansion valve by means of the refrigerant pipe.The outdoor fan is disposed to oppose the outdoor heat exchanger andpromotes the heat exchange between the outdoor heat exchanger andoutdoor air. The indoor fan introduces indoor air into the indoorapparatus and sends the air after performing the heat exchange with theindoor heat exchanger, into a room.

During a warming operation time, the refrigerant output from thecompressor by switching of the four-way valve flows through the indoorheat exchanger, the expansion valve, the outdoor heat exchanger andreturns to the compressor. According to this, the indoor heat exchangerforms a high temperature portion of the refrigeration cycle, while theoutdoor heat exchanger forms a low temperature portion of therefrigeration cycle. The indoor air rises in temperature by the heatexchange with the indoor heat exchanger and is sent into the room,whereby indoor warming is performed.

During a cooling operation time, the refrigerant output from thecompressor by the switching of the four-way valve flows in a directionopposite to the direction during the warming operation time. In otherwords, the refrigerant flows through the outdoor heat exchanger, theexpansion valve, the indoor heat exchanger and returns to thecompressor. According to this, the outdoor heat exchanger forms the hightemperature portion of the refrigeration cycle, while the indoor heatexchanger forms the low temperature portion of the refrigeration cycle.The indoor air falls in temperature because of the heat exchange withthe indoor heat exchanger and is sent into the room, whereby the indoorcooling is performed.

Besides, the outdoor heat exchanger has frost during the warmingoperation time, accordingly, a defrosting operation is performed atpredetermined intervals. During the defrosting operation time, theindoor fan and the outdoor fan are stopped, and the refrigerant flows inthe same direction as the direction during the cooling operation timebecause of the switching of the four-way valve. According to this, theoutdoor heat exchanger forms the high temperature portion of therefrigeration cycle, and the frost on the outdoor heat exchanger melts.The defrosted water due to the melting of the frost flows down the finand falls below the outdoor heat exchanger, whereby it is possible todefrost the outdoor heat exchanger.

CITATION LIST Patent Literature

PLT1: JP-A-2010-181036 (pages 4 to 6, FIG. 1)

SUMMARY OF INVENTION Technical Problem

However, according to the conventional air conditioner, the defrostedwater, which flows down the fin of the outdoor heat exchanger during thedefrosting operation time, is held between the adjacent fins by surfacetension. Because of this, in a case when the outdoors where the outdoorapparatus is installed is a low temperature in a cold area, if thedefrosting operation is stopped, the defrosted water held by the finsfreeze again. If the warming operation is performed in this state, afrost grows on the ice that freezes again between the fins, accordingly,the frost amount increases and it is necessary to shorten the intervalof the defrosting operation. Accordingly, there is a problem that theindoor warming is not sufficiently performed and comfortablenessdeclines.

It is an object of the present invention to provide an air conditionerthat is able to improve the comfortableness.

Solution to Problem

To achieve the above object, according to the present invention, an airconditioner comprising: a compressor that operates a refrigerationcycle; an indoor heat exchanger that performs heat exchange with indoorair; and an outdoor heat exchanger that performs the heat exchange withoutdoor air, the compressor is driven to perform a warming operation inwhich the indoor heat exchanger is used as a high temperature portion ofthe refrigeration cycle and the outdoor heat exchanger is used as a lowtemperature portion, and to perform a defrosting operation fordefrosting the outdoor heat exchanger in which the outdoor heatexchanger serving as the high temperature portion of the refrigerationcycle is defrosted by flowing a refrigerant in a direction opposite to adirection during a time of the warming operation, wherein in the outdoorheat exchanger, many fins are fixed to a refrigerant pipe to be close toone another, an airflow passes through between the fins to perform theheat exchange, and a water guide portion for closing a space between thefins at one end in an airflow passing direction is disposed at a lowerend of the outdoor heat exchanger.

According to this structure, during the warming operation time, bydriving the compressor, the refrigerant flows and the refrigerationcycle is operated. The outdoor heat exchanger forms the low temperatureportion of the refrigeration cycle, and the air which performs a heatexchange with the indoor heat exchanger that forms the high temperatureportion of the refrigeration cycle, is sent into a room, whereby theindoor warming is performed. At this time, the outdoor heat exchangerperforms the heat exchange with outdoor air that passes through betweenthe fins. If the outdoor heat exchanger has frost, a defrostingoperation is performed. During a defrosting operation time, therefrigerant flows in a direction opposite to the direction during thewarming operation time, and the outdoor heat exchanger forms the hightemperature portion of the refrigeration cycle. According to this, thefrost on the outdoor heat exchanger melts and the defrosted water flowsdown the fins. At this time, the defrosted water flowing down one endportion of the fins (e.g., an airflow outlet portion) is guided by thewater guide portion, which closes a lower end space between the fins, tothe other end portion (e.g., an airflow inlet portion). The defrostedwater guided by the water guide portion joins the defrosted waterflowing down the other end portion and falls below the outdoor heatexchanger.

Besides, the present invention is characterized in that in the airconditioner having the above structure, the defrosted water, which flowsdown the one end portion of the fins in the airflow passing directionduring the warming operation time, is received by the water guideportion and guided to the other end portion.

Besides, the present invention is characterized in that in the airconditioner having the above structure, the water guide portion iscomposed of a plate-shaped member having an L shape in section thatcontacts the lower end of the fins and extends in a direction in whichthe fins are disposed to be parallel with one another. According to thisstructure, the defrosted water flowing down the one end portion of thefins is guided to the other end portion by the water guide portion thathas the L shape in section.

Besides, the present invention is characterized in that in the airconditioner having the above structure, the water guide portion isformed by bending a corner portion that includes a lower surface of thefins. According to this structure, the defrosted water flowing down theone end portion of the fins is guided to the other end portion by thewater guide portion that is obtained by bending the corner portion ofthe lower end of the fin.

Besides, the present invention is characterized in that in the airconditioner having the above structure, a plurality of lines of therefrigerant pipes are disposed in a zigzag pattern in the airflowpassing direction, and a lower end of the refrigerant pipe disposed inthe one end portion in the airflow passing direction is disposed at aposition higher than a lower end of the refrigerant pipe disposed in theother end portion. According to this structure, the refrigerant pipesare disposed to be parallel with one another in the airflow passingdirection of the fins, and the water guide portion is disposed on thefin where a distance from the lower end of the fin to the refrigerantpipe is longer.

Besides, the present invention is characterized in that in the airconditioner having the above structure, in the outdoor heat exchanger,the water guide portion is disposed on a downstream side in the airflowpassing direction during the warming operation time. According to thisstructure, during the warming operation time, outdoor air performs theheat exchange with the refrigerant pipe and fins of the outdoor heatexchanger. At this time, the air passing through between the fins in alower portion collides with the water guide portion disposed in thedownstream portion and flows upward.

Besides, the present invention is characterized in that in the airconditioner having the above structure, the refrigerant pipe, which isdisposed in the high temperature portion of the refrigeration cycleduring the warming operation time, is disposed under the outdoor heatexchanger. According to this structure, the refrigerant pipe disposedunder the outdoor heat exchanger forms the high temperature portion ofthe refrigeration cycle during the warming operation time and frost on alower portion of the outdoor heat exchanger and on a bottom wall of theoutdoor apparatus is alleviated.

Advantageous Effects of Invention

According to the present invention, the water guide portion closing thespace between the fins at the one end in the airflow passing directionis disposed at the lower end of the outdoor heat exchanger. According tothis, it is possible to receive the defrosted water, which flows downthe one end portion of the fin during the warming operation time, bymeans of the water guide portion and to easily guide the defrosted waterto the other end portion. As a result of this, the defrosted waterflowing down the one end portion of the fin joins the defrosted waterflowing down the other end portion and falls downward. Because of this,the flow amount per unit area of the defrosted water guided to the lowerend of the fin increases and falls fast from the lower end of the fin.According to this, it is possible to reduce the defrosted water that isheld by the lower end of the fin because of the surface tension andreduce the frost amount on the outdoor heat exchanger. Accordingly, itis possible to prolong the interval of the defrosting operation and toimprove the comfortableness.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a circuit diagram showing a refrigeration cycle of an airconditioner according to a first embodiment of the present embodiment.

FIG. 2 is a perspective view showing an inside of an outdoor apparatusof the air conditioner according to the first embodiment of the presentinvention.

FIG. 3 is an exploded perspective view showing the outdoor apparatus ofthe air conditioner according to the first embodiment of the presentinvention.

FIG. 4 is a vertical sectional view showing an outdoor heat exchanger ofthe air conditioner according to the first embodiment of the presentinvention.

FIG. 5 is a vertical sectional view showing an outdoor heat exchanger ofan air conditioner according to a second embodiment of the presentinvention.

FIG. 6 is a view seen in an arrow D direction of FIG. 5.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention are described withreference to the drawings. FIG. 1 is a circuit diagram showing arefrigeration cycle of an air conditioner according to a firstembodiment. An air conditioner 1 has an indoor apparatus 10 disposedindoors and an outdoor apparatus 20 disposed outdoors. In the airconditioner 1, a compressor 21, which flows a refrigerant in arefrigerant pipe 2 and operates a refrigeration cycle, is disposed inthe outdoor apparatus 20.

The outdoor apparatus 20 is provided therein with: a four-way valve 22connected to the compressor 21; an outdoor heat exchanger 23; anexpansion valve 24; and an outdoor fan 25. The indoor apparatus 10 isprovided therein with: an indoor heat exchanger 13; and an indoor fan15. In the indoor heat exchanger 13 and outdoor heat exchanger 23, manyfins 30 (see FIG. 4) are fixed to the refrigerant pipe 2 to be close toone another, and perform heat exchange with air that passes throughbetween the fins 30.

The compressor 21 is connected to one end of the outdoor heat exchanger23 and one end of the indoor heat exchanger 13 via the four-way valve 22by means of the refrigerant pipe 2. The other ends of the outdoor heatexchanger 23 and indoor heat exchanger 13 are connected via theexpansion valve 24 by means of the refrigerant pipe 2. Besides, a heatpipe 26 disposed in a lower portion of the outdoor heat exchanger 23 isformed by the refrigerant pipe 2 between the expansion valve 24 and theindoor heat exchanger 13.

The outdoor fan 25 is disposed to oppose the outdoor heat exchanger 23.By driving the outdoor fan 25, outdoor air is supplied to the outdoorheat exchanger 23 and the heat exchange between the outdoor heatexchanger 23 and the outdoor air is promoted. The air performing theheat exchange with the outdoor heat exchanger 23 is exhausted to outsidevia an air outlet (not shown) that faces the outdoor fan 25 and opensfrom the outdoor apparatus 20.

The indoor fan 15 and the indoor heat exchanger 13 are disposed in anair path (not shown) formed in the indoor apparatus 10. By driving theindoor fan 15, indoor air flows into the air path to be supplied to theindoor heat exchanger 13, and the heat exchange is performed between theair flowing in the air path and the indoor heat exchanger 13. The airperforming the heat exchange with the indoor heat exchanger 13 is sentinto a room via an air outlet (not shown) that opens from the indoorapparatus 10.

FIG. 2 is a perspective view showing an inside of the outdoor apparatus20 of the air conditioner 1. Besides, FIG. 3 is an exploded perspectiveview of a main portion of the outdoor apparatus 20. In the outdoorapparatus 20, the compressor 21 is disposed on one end of a bottom plate29 that has a substantially rectangular shape when viewed from top, andthat is short in a front-rear direction and long in a left-rightdirection. The outdoor heat exchanger 23 is formed into a substantiallyL shape when viewed from top and disposed upright on a side portionopposite to the compressor 21 and a rear portion of the outdoorapparatus 20. Besides, the heat pipe 26 is disposed in the lower portionof the outdoor heat exchanger 23. A water drainage hole 29 a is disposedthrough one or more positions of the bottom plate 29 under the outdoorheat exchanger 23.

The outdoor fan 25 includes a shaft disposed in the front-rear directionand is disposed to oppose the outdoor heat exchanger 23. By driving theoutdoor fan 25, outdoor air flows mainly from a rear side of the outdoorapparatus 20 to a front side as shown by an arrow B, to perform the heatexchange with the outdoor heat exchanger 23. Meanwhile, part of the airflows into the outdoor apparatus 20 from a side to perform a heatexchange via a side portion of outdoor heat exchanger 23 and is guidefrontward.

FIG. 4 shows a vertical sectional view of the outdoor heat exchanger 23.The outdoor heat exchanger 23 is provided with, in the front-reardirection, two lines of the refrigerant pipes 2 that snake at apredetermined pitch P in a vertical direction. The refrigerant pipes 2in the front-rear direction are disposed at positions deviated in thevertical direction in a zigzag pattern. According to this, it ispossible to make the air flowing as shown by the arrow B contact therefrigerant pipes 2 in the front-rear direction, and to improve the heatexchange efficiency.

The refrigerant pipes 2 in the front-rear direction are each mountedwith a fixed rectangular fin 30 that extends in the vertical direction,and the outdoor heat exchanger 23 is composed to be a fin and tube type.The fins 30 are disposed at a predetermined pitch (e.g., 1.3 mm) to beclose to each other in a direction in which the refrigerant pipe 2extends, and an airflow passes through between the fins 30 as shown bythe arrow B. A fin 30 a is disposed on the refrigerant pipe 2 on anupstream side where the airflow passes, while a fin 30 b is disposed onthe refrigerant pipe 2 on a downstream side.

A water guide portion 31 is disposed on and contacts a lower end of thefin 30 b on the downstream side. The water guide portion 31 is formed ofa metal plate shaped member that extends in the left-right direction andhas an L shape in section, and closes a space between the adjacent fins30 b. The water guide portion 31 guides defrosted water which flows downthe fin 30 b on the downstream side, to the fin 30 a on the upstreamside during a defrosting operation time.

In the air conditioner having the above structure, during a warmingoperation time, the indoor fan 15 and the outdoor fan 25 are driven andthe four-way valve 22 is switched as shown by a solid line in thefigure. According to this, by driving the compressor 21, the refrigerantflows in a direction indicated by an arrow A, and the refrigerant, whichis compressed by the compressor 21 to be high temperature and highpressure, radiates heat in the indoor heat exchanger 13 and condenses.

The high temperature refrigerant passes through the heat pipe 26,thereafter, is expanded by the expansion valve 24 to be low temperatureand low pressure, and sent to the outdoor heat exchanger 23. Frost onthe bottom plate 29 and a lower end of the outdoor heat exchanger 23 isreduced by the heat pipe 26. Especially, the amount of frost on theoutdoor apparatus 20 oriented to a cold area increases, accordingly, theheat pipe 26 is often disposed under the outdoor heat exchanger 23.

The refrigerant flowing into the outdoor heat exchanger 23 absorbs heatand evaporates to become a low temperature gas refrigerant and is sentto the compressor 21. According to this, the refrigerant circulates andthe refrigeration cycle is operated. The air, which performs the heatexchange with the indoor heat exchanger 13 forming a high temperatureportion of the refrigeration cycle, is sent in to the room by the indoorfan 15, whereby indoor warming is performed. Besides, the air, whichperforms the heat exchange with the outdoor heat exchanger 23 forming alow temperature portion of the refrigeration cycle, is exhausted tooutside by the outdoor fan 25.

During a cooling operation time, the indoor fan 15 and the outdoor fan25 are driven and the four-way valve 22 is switched as shown by a brokenline in the figure. According to this, by driving the compressor 21, therefrigerant flows in a direction opposite to the arrow A direction,whereby the indoor heat exchanger 13 forms the low temperature portionof the refrigeration cycle, while the outdoor heat exchanger 23 formsthe high temperature portion of the refrigeration cycle. The air, whichperforms the heat exchange with the indoor heat exchanger 13, is sentinto the room by the indoor fan 15, whereby the indoor cooling isperformed. Besides, the air, which performs the heat exchange with theoutdoor heat exchanger 23 which forms the high temperature portion ofthe refrigeration cycle, is exhausted to the outside by the outdoor fan25.

Besides, the outdoor heat exchanger 23 forming the low temperatureportion of the refrigeration cycle during a warming operation has frost,accordingly, the defrosting operation is performed at a predeterminedinterval. During the defrosting operation, the indoor fan 15 and theoutdoor fan 25 are stopped and the four-way valve 22 is switched asshown by a broken line in the figure. According to this, by driving thecompressor 21, the refrigerant flows in the direction opposite to thearrow A direction, whereby the indoor heat exchanger 13 forms the lowtemperature portion of the refrigeration cycle, while the outdoor heatexchanger 23 forms the high temperature portion of the refrigerationcycle.

Because of the stopping of the outdoor fan 25, the heat exchange betweenthe outdoor heat exchanger 23 and outdoor air is alleviated, and it ispossible to efficiently raise the outdoor heat exchanger 23 intemperature. Besides, by the stopping of the indoor fan 15, it ispossible to prevent low temperature air from being sent into the room.

Because of the temperature rise of the outdoor heat exchanger 23, thefrost on the outdoor heat exchanger 23 melts and flows down the fins 30.The defrosted water, which flows down the fin 30 b in one end portion(downstream side) in an airflow passing direction, is received by thewater guide portion 31 closing the lower end and guided to the other endportion (upstream side). The defrosted water, which flows down the fin30 a on the upstream side in the airflow passing direction, joins thedefrosted water on the downstream side guided by the water guide portion31 and falls from a lower end of the fin 30 a. The defrosted waterfalling from the outdoor heat exchanger 23 is drained via the waterdrainage hole 29 a.

At this time, the flow amount per unit area of the defrosted water,which is drained from the lower end of the fin 30 on part of which thewater guide portion 31 is disposed, increases compared with a case wherethe water guide portion 31 is not disposed, and falls fast from thelower end of the fin 30. According to this, it is possible to reduce thedefrosted water that is held by the lower end of the fin 30 because ofsurface tension.

Meanwhile, if the water drainage hole 29 a is disposed under the fin 30a on which the water guide portion 31 is not disposed, the drainageimproves. In other words, by disposing the water drainage hole 29 a at aposition on which the defrosted water, which flows down the fin 30 andjoins because of the water guide portion 31, falls, it is possible toeasily drain the defrosted water via the water drainage hole 29 a.

According to the present embodiment, the water guide portion 31 closingthe space between the fins 30 b at one end in the airflow passingdirection is disposed at the lower end of the outdoor heat exchanger 23.According to this, during the defrosting operation time, by using thewater guide portion 31, it is possible to receive the defrosted waterflowing down one (fin 30 b) of the fin 30 and to easily guide thedefrosted water to the other one (fin 30 a). As a result of this, thedefrosted water flowing down the fin 30 b on one side joins thedefrosted water flowing down the fin 30 a on the other side and fallsdownward.

Because of this, the flow amount per unit area of the defrosted waterdrained from the lower end of the fin 30 increases and falls fast fromthe lower end of the fin 30. According to this, it is possible to reducethe defrosted water held by the lower end of the fin 30 because of thesurface tension and to reduce the frost amount on the outdoor heatexchanger 23. Accordingly, it is possible to prolong the interval of thedefrosting operation and to improve comfortableness.

Besides, by using the plate-shaped member having the L shape in sectionthat extends in the parallel disposition direction of the fin 30 andcontacts the lower end of the fin 30, it is possible to easily providethe water guide portion 31 that guides the defrosted water.

Besides, the heat pipe 26 (refrigerant pipe 2), which is disposed at thehigh temperature portion of the refrigeration cycle during the warmingoperation time, is disposed under the outdoor heat exchanger 23,accordingly, it is possible to reduce the frost on a bottom plate of theoutdoor apparatus 20 and a lower portion of the outdoor heat exchanger23. Instead of the heat pipe 26, a heater such as a glass pipe heater orthe like may be disposed.

Meanwhile, the water guide portion 31 may be disposed on the fin 30 onthe upstream side in the airflow passing direction during the warmingoperation time. However, if the water guide portion 31 is disposed onthe upstream side, the airflow flows in a direction opposite to thearrow B direction, and the airflow guided to the lower portion of theoutdoor heat exchanger 23 collides with the water guide portion 31 to bescattered upward and downward. Because of this, the airflow does notcontact the refrigerant pipe 2 in a lower portion that opposes the waterguide portion 31 and the fins 30 at the lower portion, accordingly, theheat exchange efficiency declines.

If the water guide portion 31 is disposed on the fin 30 b on thedownstream side in the airflow passing direction during the warmingoperation time, the airflow in the lower portion of the outdoor heatexchanger 23 performs the heat exchange with the refrigerant pipe 2 andthe fin 30, thereafter, collides with the water guide portion 31 andflows upward. According to this, compared with the case where the waterguide portion 31 is disposed on the upstream side in the airflow passingdirection, heat exchange area increases and it is possible to improvethe heat exchange efficiency.

Next, FIG. 5 shows a vertical sectional view of the outdoor heatexchanger 23 of the air conditioner 1 according to a second embodiment.Besides, FIG. 6 shows a view when seen in an arrow D direction of FIG.5. For the sake of description, the same portions as the above firstembodiment shown in FIG. 1 to FIG. 4 are indicated by the same referencenumbers. In the present embodiment, instead of the water guide portion31 (see FIG. 4) in the first embodiment, a water guide portion 32 isdisposed. The other portions are the same as the first embodiment.

The water guide portion 32 is formed by bending a corner portion thatincludes a lower surface of the fin 30 b of the outdoor heat exchanger23. Besides, the refrigerant pipes 2 are disposed in a zigzag pattern,and the lower end of the refrigerant pipe 2 disposed on the downstreamside in the airflow passing direction is disposed at a position higherthan the lower portion of the refrigerant pipe 2 disposed on theupstream side. Because of this, a distance H 2 between the lower end ofthe fin 30 b on the downstream side forming the water guide portion 32and the refrigerant pipe 2 at the lowest portion is larger than adistance H1 between the lower end of the fin 30 a on the upstream sideand the refrigerant pipe 2 at the lowest portion. According to this, itis possible to easily form the water guide portion 32 by bending the fin30 b.

At this time, the fins 30 b are disposed in parallel with one another inthe direction in which the refrigerant pipe 2 extends, and the distancebetween the adjacent fins 30 b is narrow. Because of this, the waterguide portions 32 obtained by bending the adjacent fins 30 b overlap oneanother and close the space between the adjacent fins 30 b.

The defrosted water, which flows down the fin 30 b in the one endportion (downstream side) in an airflow passing direction during thedefrosting operation time, is received by the water guide portion 32closing the lower end and guided to the other end portion (upstreamside). The defrosted water, which flows down the fin 30 a on theupstream side in the airflow passing direction, joins the defrostedwater on the downstream side guided by the water guide portion 32 andfalls. The defrosted water falling from the outdoor heat exchanger 23 isdrained via the water drainage hole 29 a.

At this time, compared with a case where the water guide portion 32 isnot disposed, the flow amount per unit area of the defrosted water,which is drained from the lower end of the fin 30 on part of which thewater guide portion 32 is disposed, increases and falls fast from thelower end of the fin 30. According to this, it is possible to reduce thedefrosted water that is held by the lower end of the fin 30 because ofthe surface tension.

According to the present embodiment, the water guide portion 32, whichcloses the space between the fins 30 at the one end in the airflowpassing direction, is disposed at the lower end of the outdoor heatexchanger 23. According to this, like the first embodiment, during thedefrosting operation time, by using the water guide portion 32, it ispossible to receive the defrosted water flowing down the one (fin 30 b)of the fin 30 and to easily guide the defrosted water to the other one(fin 30 a). As a result of this, the defrosted water flowing down thefin 30 b on the one side joins the defrosted water flowing down the fin30 a on the other side and falls downward.

Because of this, the flow amount per unit area of the defrosted waterdrained from the lower end of the fin 30 increases and falls fast fromthe lower end of the fin 30. According to this, it is possible to reducethe defrosted water held by the lower end of the fin 30 because of thesurface tension and to reduce the frost amount on the outdoor heatexchanger 23. Accordingly, it is possible to prolong the interval of thedefrosting operation and to improve the comfortableness.

Besides, it is possible to easily form the water guide portion 32 forguiding the defrosted water by bending the corner portion that includesthe lower surface of the fin 30.

Besides, the plurality of lines of refrigerant pipes 2 are disposed inthe zigzag pattern in the airflow passing direction, and the lower endof the refrigerant pipe 2 on the downstream side is disposed at theposition higher than the lower portion of the refrigerant pipe 2 on theupstream side, accordingly, it is possible to easily form the waterguide portion 32 by bending the fin 30.

Meanwhile, like the above description, the water guide portion 32 may bedisposed on the fin 30 on the upstream side in the airflow passingdirection during the warming operation time. However, if the water guideportion 32 is disposed on the fin 30 on the downstream side in theairflow passing direction during the warming operation time, comparedwith the case where the water guide portion 32 is disposed on theupstream side in the airflow passing direction, the heat exchange areaincreases and it is possible to improve the heat exchange efficiency.

In the present embodiment, structure may be employed, in which forexample, soldering is applied to the portion where the water guideportions 32 of the adjacent fins 30 b overlap to fill up a gap of theoverlapping portion. According to this structure, the gap occurring atthe overlapping portion of the water guide portions 32 is closed,accordingly, it becomes easy to guide the defrosted water on thedownstream side to the upstream side.

In the first and second embodiments, the refrigerant pipes 2 disposed inparallel with each other in the front and rear portions of the outdoorheat exchanger 23 are mounted with the fixed separate fins 30 a and 30b, however, fin common to the refrigerant pipes 2 in the front and rearportions may be disposed. In other words, each of the fins disposed inparallel with each other in the direction in which the refrigerant pipes2 extend may be fixed bridging the refrigerant pipes 2 in the front andrear portions.

Hereinbefore, the embodiments of the present invention are described,however, the scope of the present invention is not limited to theseembodiments, and it is possible to make various modifications withoutdeparting from the spirit of the present invention and put them intopractical use.

INDUSTRIAL APPLICABILITY

The present invention is usable for an air conditioner that performs awarming operation and a defrosting operation.

REFERENCE SIGNS LIST

1 air conditioner

2 refrigerant pipe

10 indoor apparatus

13 indoor heat exchanger

15 indoor fan

20 outdoor apparatus

21 compressor

22 four-way valve

23 outdoor heat exchanger

24 expansion valve

25 outdoor fan

26 heat pipe

29 bottom plate

30 fin

31, 32 water guide portions

1. An air conditioner comprising: a compressor that operates arefrigeration cycle; an indoor heat exchanger that performs heatexchange with indoor air; and an outdoor heat exchanger that performsthe heat exchange with outdoor air, the compressor is driven to performa warming operation in which the indoor heat exchanger is used as a hightemperature portion of the refrigeration cycle and the outdoor heatexchanger is used as a low temperature portion, and to perform adefrosting operation for defrosting the outdoor heat exchanger in whichthe outdoor heat exchanger serving as the high temperature portion ofthe refrigeration cycle is defrosted by flowing a refrigerant in adirection opposite to a direction during a time of the warmingoperation, wherein in the outdoor heat exchanger, many fins are fixed toa refrigerant pipe to be close to one another, an airflow passes throughbetween the fins to perform the heat exchange, and a water guide portionfor closing a space between the fins at one end in an airflow passingdirection is disposed at a lower end of the outdoor heat exchanger. 2.The air conditioner according to claim 1, wherein defrosted water, whichflows down one end portion of the fins in the airflow passing directionduring the warming operation time, is received by the water guideportion and guided to other end portion.
 3. The air conditioneraccording to claim 2, wherein the water guide portion is composed of aplate-shaped member having an L shape in section that contacts the lowerend of the fins and extends in a direction in which the fins aredisposed to be parallel with one another.
 4. The air conditioneraccording to claim 2, wherein the water guide portion is formed bybending a corner portion that includes a lower surface of the fin. 5.The air conditioner according to claim 3, wherein a plurality of linesof the refrigerant pipes are disposed in a zigzag pattern in the airflowpassing direction, and a lower end of the refrigerant pipe disposed inthe one end portion in the airflow passing direction is disposed at aposition higher than a lower end of the refrigerant pipe disposed in theother end portion.
 6. The air conditioner according to claim 1, whereinin the outdoor heat exchanger, the water guide portion is disposed on adownstream side in the airflow passing direction during the warmingoperation time.
 7. The air conditioner according to claim 1, wherein therefrigerant pipe, which is disposed in the high temperature portion ofthe refrigeration cycle during the warming operation time, is disposedunder the outdoor heat exchanger.
 8. The air conditioner according toclaim 4, wherein a plurality of lines of the refrigerant pipes aredisposed in a zigzag pattern in the airflow passing direction, and alower end of the refrigerant pipe disposed in the one end portion in theairflow passing direction is disposed at a position higher than a lowerend of the refrigerant pipe disposed in the other end portion.